Oil to Old EFM

After finishing the aquastat (Honywell L8124A) and timer wiring per EFM instruction sheet Included with timer, we were ready for fire...
Auger some coal into the pot, got some small wood scraps going, and turned on the furnace switch. Stoker blower comes on and anticipation of warm and tosty toes begins to rapidly build!

After 15 min of only the blower running, there is a flash of light and a pretty strong SNAP from the Aquastat. I reset the breaker and began checking things out with the multi-meter and double checking the wiring to the instructions. 120v in on L1 and L2 but nothing on B1 and B2. Wiring as directed. After disconnecting the aquastat and bending the tabs to reveal the backside of the board. There we find problem.

Is it possible that I got some sort of defective unit? I know how unlikely that sort of of thing is but it does happen. I would lay the blame squarely at my own feet if I didnt have instructions to follow...and if it didnt function properly for 15 min before going POP!

Guess I will go in the morning and fight with the "no return on electrical" policy at the plumbing supply co. I understand why that policy is in place, and would not feel I could make a justified argument if sparks flew as soon as I flipped the switch.

Maybe I should have specified the TYPE of fire I was looking for, eh?

Thanks for the compliment, Kevin.

Rob,
The big circulator is from my old oil fired boiler. I know it is oversized, but am planning additional runs in the future, one of which will have 100' to go underground. (to the house)

Basically, we have a primary loop with the big circ on the return side. The only zone I currently have is the radiant floor. There is a Taco 007 pulling from the primary loop and through the mixing valve.

BTW I had the large B/G circulating pump and the small zone pump wired together on C1 and C2 of the aquastat. The total amp draw of both motors is under 3 amps. The Circ circut of the aquastat is rated for 7.

Depending on the model of that big circulator, it might not be a good choice for a long piping run. Perhaps it will work fine, but usually those big boys are made to move a lot of water with very little piping resistance.

Rob,

I will certainly keep that in mind... Thanks.

Have any thoughts on the stat?

...and if anyone has an extra round door they are willing to part with, please let me know!

If you are sure it was wired properly (and it mostly was since it ran) then it sure seems like a defective control.

The second auqastat was installed Monday afternoon, and the system has since been working great! As suspected, the first stat must have been defective. Thankfully the plumbing supply company exchanged it without cost. I have the high limit set at 180 and the low at 140. The timer clicks on the stoker for 2 min every 30 min. when the water temp is below 170 (180 minus the 10 degree differential)

It chomped down approx 100-150lbs of coal to get the floor up to temp but has been just "nibbling" away since. However, the outside temperature hasnt been too cold just yet, (low 40's for highs) but it dips into the 20's at night. According the the weather forecast, we'll give 'er a good workout this weekend.

Thanks for your help and input. Im sure I'll need some more to really get it dialed in.

PS... Still looking for a round door!